• Title/Summary/Keyword: Single antenna

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Angle-of-Arrival Estimation Algorithm Based on Combined Array Antenna

  • Kim, Tae-yun;Hwang, Suk-seung
    • Journal of Positioning, Navigation, and Timing
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    • v.10 no.2
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    • pp.131-137
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    • 2021
  • The Angle-of-Arrival (AOA) estimation in real time is one of core technologies for the real-time tracking system, such as a radar or a satellite. Although AOA estimation algorithms for various antenna types have been studied, most of them are for the single-shaped array antenna suitable to the specific frequency. In this paper, we propose the cascade AOA estimation algorithm for the combined array antenna with Uniform Rectangular Frame Array (URFA) and Uniform Circular Array (UCA), with the excellent performance for various frequencies. The proposed technique is consisted of Capon for roughly finding AOA groups with multiple signal AOAs and Beamspace Multiple Signal Classification (MUSIC) for estimating the detailed signal AOA in the AOA group, for the combined array antenna. In addition, we provide computer simulation results for verifying the estimation performance of the proposed algorithm.

Performance analysis of atomic magnetometer and bandwidth-extended loop antenna in resonant phase-modulated magnetic field communication system

  • Hyun Joon Lee;Jung Hoon Oh;Jang-Yeol Kim;In-Kui Cho
    • ETRI Journal
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    • v.46 no.4
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    • pp.727-736
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    • 2024
  • Telecommunications through an electrically conductive medium require the use of carrier bands with very-low and ultralow frequencies to establish radiofrequency links in harsh environments. Recent advances in atomic magnetometers operating at very-low frequencies have facilitated the reception of digitally modulated signals. We demonstrate the transmission and reception of quadrature phase-shift keying (QPSK) signals using a multi-resonant loop antenna and atomic magnetometer, respectively. We report the measured error vector magnitude according to the symbol rate for QPSK modulation and analyze the bandwidth of a receiver based on the atomic magnetometer. The multi-resonant loop antenna noticeably enhances the bandwidth by over 70% compared with a single-loop antenna. QPSK modulation for a carrier frequency of 20 kHz and symbol rate of 150 symbols per second verifies the feasibility of demodulation, and the measured error vector magnitude and signal-to-noise ratio are 7.29% and 30.9 dB, respectively.

Design and Implementation of Single-Feed Dual-Band Circular Polarization Square Patch Antenna for GPS and DMB (GPS/DMB 수신용 단일 급전 이중 대역 원형 편파 사각 패치 안테나 설계 및 구현)

  • Yoon, Ki-Suk;Kim, Hyuck-Jin;Yang, Woon-Geun
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.19 no.2
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    • pp.138-144
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    • 2008
  • In this paper, we propose a novel single-feed dual-band circular polarization square patch antenna for GPS(global positioning system)/DMB(digital multimedia broadcasting) receiver. The proposed antenna has folded slots at the 4 corners and a diagonal slot at the center of the square patch. The measured -10 dB impedance bandwidths of the proposed antenna were 84 MHz ranging from 1.516 GHz to 1.600 GHz for the low frequency band(GPS) and 109 MHz ranging from 2.596 GHz to 2.705 GHz for the high frequency band(DMB). The measured peak linear antenna gains of the proposed antenna were 6.23 dBi at 1.575 GHz for GPS and 6.97 dBi at 2.642 GHz for DMB band.

Fabrication of CSLR-loaded Inset Fed Patch Antenna with a Conducting Reflector (반사판을 갖는 인셋 급전 CSLR 패치 안테나 제작)

  • Hong, Jae-Pyo;Kim, Byung-Mun;Son, Hyeok-Woo
    • The Journal of the Korea institute of electronic communication sciences
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    • v.11 no.11
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    • pp.1047-1052
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    • 2016
  • In this paper, we propose the CSLR(: Complementary Single Loop Resonators)-loaded inset fed patch antenna with a conducting reflector to improve the radiation patterns. Reflector of the proposed antenna is located below about ${\lambda}_0/4$ from the ground plane of the patch, the size is about two times of the patch. The proposed antenna is designed and fabricated on the substrate which has a dielectric constant and thickness with 2.5 and 0.787 mm, respectively. Simulation results are obtained by using the HFSS, 3D EM Solver based Finite Element Method(: FEM). The resonant frequency and matching characteristics of the antenna with reflector are substantially the same as when there is no change in the antenna without reflector, it is confirmed that radiation patterns are significantly improved by the reflector.

Studies on IF noise caused by transmitter signal leakages of the W-band homodyne FMCW radar with a single antenna configuration (단일 안테나를 사용하는 W-대역 호모다인 FMCW 레이더의 누설신호에 의한 IF 잡음에 관한 연구)

  • Park Jung-Dong;Kim Wan-Joo
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.42 no.7 s.337
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    • pp.49-56
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    • 2005
  • In this paper, we describe a solution to improve the effects of the transmitter leakage signals on the frequency modulated continuous wave (FMCW) radar with a single antenna configuration. We analyze characteristics of the IF noise caused by insufficient isolation between transmitter and receiver. The magnitude of the intermediate frequency (IF) noise from a front-end can be reduced by matching the LO signal delay time with that of the largest leakage source. Because the IF noise has periodic singularities at nT$_{m}$/2, t=0,1,2$\cdots$, we find that spectrum of the IF noise due to the leakage signals is very similar to that of the VCO moduation signal except low frequency elements in the vicinity of DC. Based on the studies, we fabricated a W-band homodyne FMCW radar sensor and verified the proposed solution. The results are applicable to design of the homodyne FMCW radar with a single antenna configuration.

Improvement Transmission Reliability between Flight Type Air Node Using Concatenated Single Antenna Diversity (비행형 에어노드의 데이터 전송 신뢰성 향상을 위한 연접 단일 안테나 다이버시티 시스템)

  • Kang, Chul-Gyu;Kim, Dae-Hwan
    • Journal of Advanced Navigation Technology
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    • v.15 no.6
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    • pp.1053-1058
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    • 2011
  • In this paper, we propose a concatenated single antenna diversity system to assure the data transmission reliability between flight type air nodes which move according to their atypical orbit, then analyze its performance. The proposed system achieve a diversity gain using single antenna and a coding gain from convolutional code simultaneously. Simulation result about the bit error rate(BER) of the proposed system shows that its BER performance is about 9.5dB greater than convolutional code at $10^{-4}$ and about 14dB greater than space time block code at $10^{-3}$ which has a full diversity gain. In addition, compared with space time trellis code with diversity gain and coding gain, the proposed system shows the better 4dB at a BER of $10^{-5}$. Therefore, it is necessary that concatenated single antenna diversity should be adopted to the reliable data transmission of flight type air nodes.

The Design of a Wideband E-plane Phased Array Antenna using W/G Simulator (도파관 시뮬레이터를 이용한 광대역 E-평면 넛치 위상 배열 안테나 설계)

  • 김준연;소준호;임중수
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.14 no.2
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    • pp.111-118
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    • 2003
  • Notch Antenna is a travelling wave type antenna and can provide multioctave operation in phased arrays that scan over wide angle. In this paper, we designed a wideband E-plane phased array antenna using E-plane waveguide simulator which has a bandwidth of 3 : 1 and a scan volume of $\pm$45$^{\circ}$ in E-plane. We compared impedance of single antenna and infinite array antenna using equivalent circuit modeling. We analyzed full structure of 1$\times$9 phased array antenna and we evaluated active reflection coefficient with variation of beam scan angle through mutual coupling coefficient acquired from simulation and investigated the variation of antenna gain with variation of active element pattern as beam scan angle is varied.

RFID Noise Reduction Using a Multi-Coil Antenna (다중 코일 안테나를 이용한 RFID 유도 잡음의 감소)

  • Lee, Seong-Ho
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.19 no.6
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    • pp.603-611
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    • 2008
  • In this paper, we introduce a multi-coil antenna which is useful for reducing the effects of radio frequency noise in an inductively coupled RFID system. A multi-coil antenna is composed of a central coil and four subsidiary coils that are connected in series. A multi-coil antenna is designed so that the total noise disappear when the induced voltages of a central coil and subsidiary coils are added. The noise in a multi-coil antenna was about 30 dB lower than that in a single coil antenna. The multi-coil antenna is very effective in noise reduction even in an environment that the spatial distribution of RF noise is changed abruptly, and the induced noise was about 16 dB lower than that in a dual coil antenna.

Design and Implementation of An Active Antenna for Vehicle (차량용 통합 능동형 안테나의 설계 및 제작)

  • Kim, Sang-Uk;Go, Min-Ho;Jo, Yun-Hyun;Park, Hyo-Dal
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.8 no.4
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    • pp.39-45
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    • 2009
  • In this paper, designed and fabricated the microstrip antenna using parasitic plane. This active antenna for the use of AM/FM, DMB(Digital Multimedia Broadcasting), GPS(Global Positioning System) band in vehicle. Fabricated active antenna was compared to existing planar antenna represents more than 15% size reduction and equivalence performance compared to commercial helical antenna. And satisfy performance in DMB, GPS band. This active antenna composed of single input port and two output ports and entire size of antenna is $133{\times}31{\times}1.2mm$.

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Forced Resonant Type Cutoff Cavity-Backed Aperture Antennas Loaded with a Single External Reactance

  • Kim Ki-Chai;Hirasawa Kazuhiro
    • Journal of electromagnetic engineering and science
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    • v.5 no.3
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    • pp.105-111
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    • 2005
  • This paper presents the basic characteristics of a cutoff cavity-backed aperture antenna with a feed post and a parasitic post inserted parallel to the aperture. It is shown that this type of antenna forcibly resonates the cutoff cavity by adding a single external reactance to the parasitic post. The Galerkin's method of moments is used to analyze integral equations for the unknown electric current on each post and the aperture electric field on the aperture. The value of an external reactance for forced resonance is analytically obtained by deriving a determining equation. Also the current distribution on each post, aperture electric field distributions, and the radiation patterns are discussed. The theoretical analysis is verified by the measured return loss and radiation patterns.